Any number have a liking for sex (5)
I believe the answer is:
digit
'any number' is the definition.
(I've seen this in another clue)
'have a liking for sex' is the wordplay.
'have a liking for' becomes 'dig' (to dig something is to appreciate it).
'sex' becomes 'it' (a common euphemism).
'dig'+'it'='DIGIT'
(Other definitions for digit that I've seen before include "Need a bit of a hand" , "a number less than ten" , "that's on hand" , "Finger, thumb or toe" , "Like It?" .)